Metallica, Slayer, Megadeth and Anthrax have announced they will tour together next year. After weeks of rumours, the bands collectively dubbed the "Big Four" of thrash metal have confirmed they will play the Sonisphere festivals across Europe in summer 2010.

A post on Metallica's website titled "The rumours are true" confirms that the four giants of metal will "share the same stage for the first time ever."

Lars Ulrich, drummer with Metallica, is quoted as saying: "Who would have thought that, more than 25 years after its inception, thrash metal's big four would not only still be around and more popular than ever, but will now play together for the first time."

Anthrax's Scott Ian added: "I believe not only will we live up to the expectations, we will shatter them", while Slayer's Kerry King added: "This is fucking awesome."

The Big Four have confirmed in a press release that they will play two legs of the Sonisphere tour, Poland and the Czech Republic. Further dates are expected to be added in the coming weeks, including one in Knebworth, England. It is not yet known whether they will tour the US.